https://github.com/mmzeeman/educkdb

DuckDB NIF for Erlang
https://github.com/mmzeeman/educkdb

Last synced: 18 days ago
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DuckDB NIF for Erlang

• Host: GitHub
• URL: https://github.com/mmzeeman/educkdb
• Owner: mmzeeman
• License: apache-2.0
• Created: 2022-01-24T21:52:11.000Z (almost 3 years ago)
• Default Branch: master
• Last Pushed: 2023-02-27T10:48:20.000Z (over 1 year ago)
• Last Synced: 2024-10-12T04:31:23.928Z (about 1 month ago)
• Language: C++
• Size: 6.41 MB
• Stars: 18
• Watchers: 2
• Forks: 1
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# educkdb

[![Hex.pm version](https://img.shields.io/hexpm/v/educkdb.svg)](https://hex.pm/packages/educkdb)

[![Hex.pm downloads](https://img.shields.io/hexpm/dt/educkdb.svg)](https://hex.pm/packages/educkdb)

```

Build disabled, github's vms are too small to build duckdb amalgation build

[![Test](https://github.com/mmzeeman/educkdb/actions/workflows/test.yml/badge.svg)](https://github.com/mmzeeman/educkdb/actions/workflows/test.yml)

```

DuckDB NIF for Erlang. 

DuckDB (https://duckdb.org/) is an in-process SQL OLAP database management system. This library makes it possible to 

use DuckDB in Erlang, Elixir or other languages supported by the beam.

# Example

Connect to a database

```erlang

{ok, Db} = educkdb:open("database.db"),

{ok, Conn} = educkdb:connect(Db)

...

```

Create a table by reading a CSV or parquet files.

```erlang

{ok, _} = educkdb:query(Conn, "CREATE TABLE ontime AS SELECT * FROM 'test.csv'"),

{ok, ParquetData} = educkdb:query(Conn, "SELECT * FROM 'test.parquet'"),

...

```

# API

*Note: This is a work in progress. At the moment it is possible to open, connect, query and return integer and

varchar results. The nif function returning the query result will become a yielding nif. This is important for

large query results.*

### Startup

#### `open(filename, options)` -> `{ok, DB}` | `{error, msg}` 

Note: (**dirty scheduler**) 

#### `connect(db)` -> `{ok, Conn}` | `{error, msg}`

Note, creates a nif thread with a command queue, all calls which uses the 

connection as parameter will be send to the thread via the queue.

#### `disconnect(connection)` -> `ok` | `{error, msg}`

Note: **via command thread**.

Explicitly disconnect the connection. This also explicitly finalizes the thread.

It is not required to call this. The garbage collector will disconnection 

automatically.

#### `close(db)` -> `ok` | `{error, msg}`

Note: (**dirty scheduler**)

Explicitly close the db. It is not required to call this. The garbage collector 

will disconnection automatically.

### Querying

#### `query(Conn, Query)` -> `{ok, QueryResult}` | `{error, msg}`

Note: **dirty scheduler**

Run a query, return the result.

### Prepared Statements

#### `prepare(Conn, Query)` -> `{ok, Stmt}` | `{error, _}`

Note: **dirty scheduler**

#### `bind(Stmt, Values)` -> `ok` | `{error, _}`

Note: **direct c**

#### `bind_null(Stmt, Index, Value)` -> `ok` | `error`

Note: **direct c**

#### `bind_boolean(Stmt, Index, Value)` -> `ok` | `error`

Note: **direct c**

#### `bind_int8(Stmt, Index, Value)` -> `ok` | `error`

Note: **direct c**

#### `bind_int16(Stmt, Index, Value)` -> `ok` | `error`

Note: **direct c**

#### `bind_int32(Stmt, Index, Value)` -> `ok` | `error`

Note: **direct c**

#### `bind_int64(Stmt, Index, Value)` -> `ok` | `error`

Note: **direct c**

#### `bind_hugeint(Stmt, Index, Value)` -> `ok` | `error`

Note: **direct c**

#### `bind_uint8(Stmt, Index, Value)` -> `ok` | `error`

Note: **direct c**

#### `bind_uint16(Stmt, Index, Value)` -> `ok` | `error`

Note: **direct c**

#### `bind_uint32(Stmt, Index, Value)` -> `ok` | `error`

Note: **direct c**

#### `bind_uint64(Stmt, Index, Value)` -> `ok` | `error`

Note: **direct c**

#### `bind_float(Stmt, Index, Value)` -> `ok` | `error`

Note: **direct c**

#### `bind_double(Stmt, Index, Value)` -> `ok` | `error`

Note: **direct c**

#### `bind_date(Stmt, Index, Value)` -> `ok` | `error`

Note: **direct c**

#### `bind_time(Stmt, Index, Value)` -> `ok` | `error`

Note: **direct c**

#### `bind_timestamp(Stmt, Index, Value)` -> `ok` | `error`

Note: **direct c**

#### `....more`

#### `execute_statement(Stmt)` -> `{ok, result()}` | `{error, _}`

Note: **dirty thread**

### `appender`

#### 

## Implementation notes

 * https://potatosalad.io/2017/08/05/latency-of-native-functions-for-erlang-and-elixir

 * https://github.com/vinoski/bitwise